Exhaust pipe



M. HOFER EXHAUST PIPE May 19, 1959 2 Sheets-Sheet 1 Filed Feb. 8, 1955 VmvENToR MAX Hon-:R

BY Mugj ATTORNEYS May 19, 1959 M. Hol-ER 2,886,945

EXHAUST PIPE Filed Feb. 8. 1955 2 Sheets-ShamI 2 INVENTOR MAX HOFERATTORNEYS United States Patent O i EXHAUST PIPE Max Hofer, Augsburg,Germany, assiguor to Maschinenfabrik Augsburg-Numberg A.G., Augsburg,Germany, a corporation of Germany This invention relates to exhaust pipeconstructions and, more particularly, to such constructions formulticylinder internal combustion engines in which the exhaust gases areutilized for driving an exhaust gas turbine.

Since the individual cylinders of multicylinder internal combustionengines lire and exhaust at different times and are located dilerentdistances from the end of the exhaust pipe which is connected to anexhaust gas turbine, it is desired to collect and conduct separately tothe turbine the exhausted gases from different cylinders or differentgroups of cylinders so that the exhaust pressure impulses lfrom thevarious cylinders do not interfere with each other. Particularly withlarge multicylinder Diesel engines, the exhaust pipe may be quite longso that provision must be made to compensate for the longitudinal heatexpansion thereof. lf separate exhaust pipes are provided for eachindividual cylinder or group of cylinders, either led separately orwithin a common casing to the exhaust turbine, the expense andcomplexity or" the construction problem is multiplied, and, especiallywith regard to engines having a V-shaped arrangement of cylinders, thequestion of adequate space becomes important.

According to the invention, however, an exhaust pipe construction isprovided to be assembled from a plurality of substantially identical orsimilar individual units mounted in end-toend relation, with the lengthof each unit corresponding approximately to the distance between theaxes of adjacent cylinders, and with each unit comprising a plurality ofseparate spirally congured gas conducting channels. Furthermore, eachunit is a substantially complete entity, including an individual waterjacket, so that interchange or replacement of the single unit is quitereadily accomplished, and the cost and complexity of constructionreduced.

lt is accordingly one object of this invention to provide an exhaustpipe construction of the character described having a plurality ofseparate units including integral internal gas channels for mounting inend-to-end relation to form the exhaust pipe.

A further object of this invention is to provide at `the adjacent endsof such units and their channels means for compensating for longitudinalthermal expansion movement thereof with respect to each other .and formaintaining a gas-tight joint at the junctures' of the separate channelsin each unit during longitudinal heat expansion movement thereof.

Another object of this invention is to provide,in an exhaust pipe of thecharacter described, a plurality of readily interchangeable units eachof which has individual cooling means and a number of separate exhaustgas channels.

Other objects and advantages of the present invention will be apparentfrom the following description, the accompanying drawing and theappended claims.

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In the drawing,

Fig. 1 shows a longitudinal section pipe embodying the invention;

Fig. 2 is a transverse section on the line II-II of Fig. l on anenlarged scale;

Fig. 3 is a section on the line III-III of Fig. 2 on an enlarged scale;j

Fig. 4 is a detail of the juncture of two individual units, inlongitudinal section and on an enlarged scale; and Fig. 5 is atransverse section along the line of Fig. 1. i

Referring to the drawing, a preferred embodiment of this invention isillustrated as an exhaust pipe construction particularly adapted to aneight cylinder Vftype internal combustion engine. The exhaust pipe(Fig. 1) comprises a plurality of individual units 1 and 2 which aresubstantially similar to each other. Each of the units 1 and 2 has anouter casing or jacket S within which are a plurality of integrallongitudinal partitions 6, and each unit has a socket or connection 7through each of which exhaust gases of two of the eight cylinders areintroduced. It will be noted that the length of the individual units 1and 2 corresponds approximately to the distance between the axes ofadjacent cylinders.

In the illustrated embodiment, the cross section of the outer casing 5is divided into four separate channels by the partition 6-i.e., onechannel for each pair of cylinders. Thus, considering the cylinderstiring or exhausting in pairs, the exhaust impulses are led from eachcylinder or group of cylinders to the exhaust gas turbine (not shown)through a separate channel within the casing 5 without admixture orinterference with the exhaust gas impulses of other cylinders tiring andexhausting at a dilerent moment. It will be understood, of course, thatthe number of separate channels formed by partitions 6 may be varied anddepends upon the number of different cylinders and/or groups ofcylinders which tire and exhaust at different moments.

The internal partition 6 of each unit 1 and 2 is preferably congured asindicated in Fig. 1 to form the separate channels having a substantiallyspiral configuration for a portion of the length of 4the unit and asubstantially ilat conliguration for the remainder of the length. Asindicated in Fig. l, the units l and l2 are assembled in end to endrelation to form" the exhaust pipe construction with the spiral channelends of each unit pointing in opposite directions. The extent of thespiraling is preferably determined by the number of in dividual channelswithin each unit. In the illustrated embodiment, there being fourchannels, the extent of the annular displacement of a given channel atone end `of a unit with respect to the position of that same chan nel atthe opposite end of the unit amounts to approximately but with athree-channel unit, such displacement preferably would amount to etc.VFor sim plicity of` construction, as noted in Figs. 3 and 4, the outercasing 5 and its integral internal partitions 6 are preferably cast froma single piece of heat resistant steel.

As 'shown more particularly in Fig. 4, adjacent ends ofthe outer casing5 of each unit 1 or 2 are provided with an interlitting sliding ortelescoping` joint including an outer portion 21*dimensioned for slidinginteritting engagement around the opposite end 22 of the outer casing S.This arrangement provides a substantially gas-tight seal or jointbetween adjacent units while permitting for longitudinal thermalexpansion movement of the individual units with respect to each other.Internal sealing members 8 are provided for separately sealing theindividual gas channels at the junctures thereof between adjacent units,This member 8 is rotatably xed to a central through an exhaust assautsboss 9 at one end ofthe internal partition 6 as Vby means of a bolt 23,while the opposite face of sealing member 8 interftts slidably with agroove l@ in the opposite end of the internal partitions 6 to provide agasltight joint ldes'pite longitudinal thermal expansion movement ot theindividual units relative to each other. Also the rotatability of themember 8 about the bolt 23 aids in elim inating and equalizing anyproduction inaccuracies of the intertttingunits or the partitions 6therein.

The outer casing of each unit is 'surrounded with a layer 11 of heatinsulating material and, outside layer '11, a Water jacket l2 forcoolant circulation. Jacket i2 is formed as a double tube on each unit land 2 sealed at each end with a Welded flange i3. Flange 13 also servesto connect the individual units l. and 2 as by means Vof bolts 14. Thevwater jacket on eachlunit l or 2 is preferablyindependent of waterjackets on 'other units, and `isprovided with two inlets 15, a` gutter16and a discharge opening 17 for 'coolant circulation. The exhaustconnecting sockets 7 to the individual cylinders through which exhaustgases are introduced from the.. individual cylinders arelikewise-surrounded 4by the water jacket which is sealed around'socket 7by asealing iiange 18 which also servesk as a means for connecting thesocket 7 to the individual cylinder connections 19 as-by means of -boltsor screws (not shown) in known manner.

As will be apparent from the foregoing description, developing anexhaust `pipe construction in this manner and fastening it to theinternal combustion engine primarily at water jacketed portions thereofpermits the outer jacket S and its internal partitions 6 to shiftaxially in each unit as necessitated by thermal expansion, while thewater jacket 12 and the connections 1S to the cylinder outlets are notsubject to substantial heat expansion movement because of the insulationand cooling. For easier production of the water jacket l2, it preferablyconsists of four semicylindrical parts which are Welded together aroundthe sealing flanges 1S and 13, as well as along longitudinal seams 20,to form a water-tight double pipe. Because of the individuality of thewater jackets l2 in each unit It and 2 and the interconnection thereofby the bolts 14 through flanges 13, the exhaust pipe is formed from aplurality of complete individual units each substantially free of jointsor areas for gas or coolant leakage into or out of the pipe. At one endof the illustrated embodiment, a water cooled connection ring 24 isshown for connection to an exhaust gas turbine, while the oppo- 'siteend of the pipe is sealed 0E by a suitably insulated cover 25.

It will accordingly be seen that, by the foregoing, an exhaust pipeconstruction is provided for multi-cylinder internal combustion enginesin which the exhaust impulses from individual cylinders or groups ofcylinders are separately led to an exhaust gas turbine, and yetprovision is made for longitudinal heat expansion of the yheatedportions of the exhaust pipe, as well as for the ready repair and/orreplacement of the individual seltcontained units thereof.

While the forms of apparatus herein describedconstitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to Vthese precise forms of apparatus, and that changesYmay be made therein without departing from the scope of the inventionwhich is defined in the appended claims.

What is claimed is:

1. An exhaust pipe construction for multicylinder internal combustionengines comprising in combination a plurality of similar individualunits for mounting in endto-end relation to form said pipe, an outercasing in each said unit, a plurality of internal longitudinalpartitions defining Within said casing a plurality of separatelongitudinal passages, said partitions being substantially planarthroughout approximately one-half the length of each said unit andhelically configured throughout the remaining portions of the length ofeach said unit, and means for mounting said units in end-to-end relationwith vsaid helically configured channel portions of adjacent units tacinin opposite directions, said mounting means-including means on adjacentends of said casing and said partitions for compensating forlongitudinal thermal expansionmovement of said units with respect toeach other.

2. An exhaust pipe construction for multicylinder internal combustionengines comprising in combination a plurality of identical individualunits for mounting in end-to-end relation to form said pipe, an outercasing on each said unit, a plurality of internal longitudinal partitions defining within said casing'a plurality of separate longitudinalpa-ssages,said partitions being substantially straight throughout asubstantial portion of the length of each said unit and helicallycongured throughout the remaining portion of the length of eachsaidunit, means for mounting saidunits in end-to-end relation in pairs withsaid helicalty configured portions faced together in each said pair ofunits, and means for mounting a plurality of said pairs of units inend-toend relation with said straight portionsV of said partitionstherein faced together, said mounting means including means on adjacentends of each said casing and said partitions for compensating forlongitudinal thermal expansion movement of said units with respect toeach other.

3. An exhaust pipe construction as recited in claim 2 in `which thelength of each said individual unit corrcspouds approximately to thedistance between the exhaust outietsof adjacent cylinders of said engineand said individual units including means for introducing the exhaustgas of dierent cylinders into different ones of said separatelongitudinal passages.

4. An exhaust pipe construction as recited in claim 2 includinginteltting sealing members on adjacent ends of said individual units formaintaining a substantially gas-tight seal between adjacent units duringlongitudinal thermal expansion movement thereof with respect to eachother.

5. An exhaust pipe construction as recited in claim 2 includingindividual and separate water jacket means for each said individualunit.

6. An exhaust pipe construction as recited in claim 2 includingindividual water jacket means around each unit substantiallyindependentof the water jackets on other said units, said water jacket meansincluding means for coupling said units in end-to-end relation and meansfor mounting said units on said engine.

References Cited in the le of this patent UNITED STATES PATENTS

